What is…
sardonyx

also known as: red onyx

Sardonyx is mentioned in the foundations of the coming New Jerusalem.

The foundation stones of the city wall were adorned with every kind of precious stone. The first foundation stone was jasper; the second, sapphire; the third, chalcedony; the fourth, emerald; the fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, topaz; the tenth, chrysoprase; the eleventh, jacinth; the twelfth, amethyst. … —Revelation 21:19-21 LSB excerpt

Like the sardine ston (sardius)e, it is a variety of the chalcedony. Sardonyx is a type of carnelian combining the sard (shades of red) and the black onyx.

More information

• What is onyx?
• About precious stones in the Bible
• Book of Revelation